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Don Desfosse

  • ATC Instructor
  • 5796
RNAV DP Discussion, Tips and Tricks
« on: August 06, 2011, 11:57:12 am »
A pilot had asked several questions about RNAV DPs on the VATUSA forums, and I offered the following reply to the thread.  I'm reproducing it here in the hopes that it helps.

Quote
Q: Ok - flying RNAV DPs is the only way to proceed with departure without radar vectors (most of the time) correct?
A: affirm depending on the RNAV some start literally the second your in the air others they will give you vectors to the first fix before telling you to fly the what ever you have filed
Q: Do I get to choose which departure procedure I want to do, or is that something that is sort of randomly assigned by ATC?

The point behind the RNAV DPs is that you are using them the second you are in the air; no vectors required.

1. File a real world assigned routing.  A great place to find these is here
2. Decide that whatever is done in the RW is what you want to fly :)
3. File the RNAV DP and the transition if applicable

For example, Boston just added 8 new RNAV DPs in the past 9 months.  It used to be that if you wanted to fly KBOS-JFK, you would normally file:
LUCOS SEY PARCH CCC ROBER

ATC would normally assign the LOGANx (where x is the current number, e.g. LOGAN6) Departure, which is a radar vector DP.  Assuming you filed the above, your clearance would normally sound like:
"American 123, cleared to Kennedy via the LOGAN6 departure, radar vectors LUCOS, then as filed.  Climb via SID...." 

So even though you wouldn't file LOGAN6, ATC would assign it.

But life has changed. One of the 8 new DPs at Boston is the SSOXS DP (currently the SSOXS4).  AND, Boston now uses RNAV DPs as a standard/default.

So, nowadays you'd file:
SSOXS(x) BUZRD SEY PARCH(x) (x indicating the departure #, e.g. SSOXS4)

Your clearance would normally sound like:
"American 123, cleared to Kennedy via the SSOXS4 RNAV Departure, SSOXS, then as filed. Climb via SID...."


Note how Climb via SID phraseology is used (replacing the "maintain 5000. Expect FLxxx 10 minutes after departure). That's because, in most RNAV DPs, the initial altitude to maintain is written right into the DP. More information regarding when Climb via SID can be used is located here.


Other example.  Nowadays, for airports that now use RNAV DPs as a standard, even pilots who file an "old" route but indicate that they are advanced navigation capable (GPS, RNAV, INS, etc.) will likely receive an RNAV DP in their clearance.

For example, JOE123 files KBOS-KJFK with a route of BUZRD SEY PARCH CCC ROBER and is flying a H/B744/G.  Guess what.  His clearance will be via the SSOXS4 RNAV Departure, SSOXS, BUZRD then as filed.

These RNAV DPs are springing up across the country fast and furious.  Since many pilots are still using default aircraft and/or GPSs with default navigation fixes, it's entirely possible that many pilots may not be able to navigate to all the new fixes on all these new RNAV DPs.  The FAA recommends that pilots who cannot, or do not wish to, fly STARs and/or DPs file "No DP/STAR" in their flight plan.  My suggestion for pilots who cannot, or do not wish to, fly RNAV DPs is to include "No RNAV DPs" in their flight plan, or at least verbally tell the clearance delivery controller that they do not wish an RNAV DP.  This practice would greatly aid the controller who is trying to figure out quickly and efficiently which DP to assign.  Because if you don't, here's what could happen (happens every day at KBOS nowadays....):

1. Pilot files KBOS-KJFK with a route of BUZRD SEY PARCH CCC ROBER and is flying a H/B744/G. 
2. Pilot is cleared via the SSOXS4 RNAV Departure, SSOXS, BUZRD, then as filed.
3. Pilot reads back his clearance (and therefore accepts the RNAV DP!!!)
[some intermediate steps omitted for brevity]
4. Pilot takes off and heads straight out, or turns directly toward BUZRD, or does some other wacky thing....
5. Controller asks AAL123 where he's going
6. Pilot says, "Straight out" or "Direct BUZRD" or "The controller never gave me a heading" or "Gee, I dunno...."
7. Controller gently reminds pilot that he was cleared for the RNAV DP and therefore should be following it
8. Pilot complains loudly that he can't fly the RNAV DP and the controller screwed up by giving it to him....
Yadda yadda yadda


A fellow VATSIM pilot, Graham Mitchell, has graciously developed and shared with the community updates for the default MSFS GPS.  These can be found on his website: http://www.btinternet.com/~gb.mitch/index.html  A discussion can be found on the VATSIM forums: http://forums.vatsim.net/viewtopic.php?f=28&t=30992  With these updates, it is possible to fly the RNAV DPs (and STARs as well) by using the GPS.  It's a bit of plugging in direct-to waypoints fast and furious right after takeoff, but it can certainly be done. 


We're all in this together, and we all want to have a good time.  Situations like the above are frustrating for everyone.  That said, hopefully the explanation and tips and tricks provided here help a little bit!
« Last Edit: June 17, 2015, 10:17:40 pm by Guest »
Don Desfosse (DO)
Division Director Emeritus, VATUSA
ATM Emeritus, Boston ARTCC

Boston ARTCC - Where Excellence is Routine!

Re: RNAV DP Discussion, Tips and Tricks
« Reply #1 on: August 06, 2011, 03:54:47 pm »
Thanks for the excellent explanation, DO. I always file the RNAV when it's available - however, departing from Boston, it appears that the pilot is not always required to fly the entire RNAV procedure. The controller often issues "proceed direct LUCOS" before or after reaching the first RNAV waypoint. That's fine with me because the faster I can get a more direct route to my destination, the faster I can reach that destination. Regardless, it's important that the pilot program the entire RNAV procedure in the FMS when issued. If traffic's heavy, the controller may be too busy to issue a shortcut so the next best thing is to fly the procedure as published.

Most RNAV departures I've encountered at ARTCCs other than Boston are adhered to. When a good Center controller gets a hold of you while still flying the RNAV departure, a "cleared direct to" some waypoint is often issued to expedite the departure.

There's some confusion for me about which RNAV procedure to file when departing Boston to a particular destination. For example, if GLYDE is in your manifest, and you're heading to Atlanta, which RNAV departure makes most sense? Or MHT, PSM, BOSOX, etc.?

With a mix of sophisticated and not so sophisticated pilots, the challenge is to remain patient while attempting not to neglect the pilot who knows how to fly RNAV while being consumed by one that doesn't.

The simple answer is to file as you suggested to avoid the confusion later.
Jack Gilbert

Re: RNAV DP Discussion, Tips and Tricks
« Reply #2 on: August 09, 2011, 10:39:52 pm »
Thanks for the info Don


Stephan Faessler (FR) // vZBW Controller S2
AI Repainter // Occasional VATSIM Crash Pilot

Re: RNAV DP Discussion, Tips and Tricks
« Reply #3 on: September 17, 2011, 06:34:31 pm »
I can add some to this. If you pilots dont want to input point by point while flying.
1. while on the ground before taxi, pull up the chart and look at what points you need.
2. open the 1st tab in the menu options and click the flight planner.
3. Assuming you've downloaded the bgls, you can zoom in to the KBOS area and see the RNAV points usually depicted as a blue triangle or magenta triangle. (Normally the magenta are actual fixes of of vors). Drag the red line to each point along your DP.
4. Before taking off make sure your Autopilot Nav mode is set to GPS. Normally there is a switch in the cockpit marked NAV/GPS. If there isnt one set it in the options under key assignments.
5. Fly the DP adhering to Altitude Restrictions.

Hope this helps

Re: RNAV DP Discussion, Tips and Tricks
« Reply #4 on: October 20, 2011, 07:13:34 pm »
Excellent tutorial, DO. I'm a bit shy about controlling these days because I'm uncertain about which RNAV departure to assign based on the pilot's direction of flight. When I do get back into controlling, I'll ask for an OTS or some training. I'd rather be comfortable and correct. Flying them is a different story - I fly them online all the time - and prefer them to the old departures. And as mentioned, several senior controllers from other ARTCCs issue shortcuts to waypoints after the RNAV waypoints which makes it convenient to be on course to your destination.
Jack Gilbert

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Don Desfosse

  • ATC Instructor
  • 5796
Re: RNAV DP Discussion, Tips and Tricks
« Reply #5 on: October 21, 2011, 01:22:30 am »
Ah, I certainly understand.  I was quite gunshy at first as well.  I created a small cheat sheet on a 3x5 card and have it resting on the windowsill next to my computer.  It looks something like:
[font=COURIER:365xxuzu]BLZZR     WEST     CTR/BAF/BDL/NELIE     ONEPS..BAF
BRUWN     S/SE     ACK
CELTK     E/SE     FRILL
HYLND     NW       MHT
LBSTA     NE       ENE
PATSS     W        BDL/NELIE             PATSS..BDL/NELIE
REVSS     W        CTR/BAF/BDL/NELIE     SPENO..CTR
SSOXS     S        BUZRD[/font:365xxuzu]

It is good enough of a cheat sheet that I get by just fine with it.  The only one that throws me sometimes is BLZZR vs. PATSS vs. REVSS.  If I have time, I look it up on flighaware.  For example:

http://flightaware.com/live/findflight/KBOS/Kxxx  (replacing xxx with the destination, of course) and then clicking on one of the flights

http://flightaware.com/live/findflight/KBOS/KDFW
BLZZR ONEPS BAF Q406 BWZ J6 LIT BYP5

http://flightaware.com/live/findflight/KBOS/KLGA
PATSS BDL BDL255 VALRE HAARP1

http://flightaware.com/live/findflight/KBOS/KSDF
REVSS SPENO CTR HNK PSB APE RDSTN2

Hope this helps!
« Last Edit: June 17, 2015, 10:18:50 pm by Guest »
Don Desfosse (DO)
Division Director Emeritus, VATUSA
ATM Emeritus, Boston ARTCC

Boston ARTCC - Where Excellence is Routine!

Re: RNAV DP Discussion, Tips and Tricks
« Reply #6 on: October 21, 2011, 09:15:19 pm »
From a real world pilot perspective, I can tell you there are quite a few of the RNAV SIDS that have overlapping departure gates. Our company (the dispatchers, specifically) do not file us on a particular SID.  Rather, they just file the first departure fix.  When we get out ATC clearance, we have our RNAV SID assigned, that contains the appropriate transition.

Also of note, yesterday was day 1 of the FAA's NYC/PHL airspace redesign project. A big change I overheard yesterday was the change from J routes to Q routes enroute.  Q routes are basically just RNAV airways, so they can design the airspace to work more efficiently.  A lot of the NYC departures changed. There are a few new departure gates.  I don't think any of them change routing up to Boston. 

Can post a follow up tomorrow.  Flying JFK-BOS-JFK-BOS-JFK-ORD.  I wonder if we'll get assigned one of these Q routes or not.

Things that make you go hmmm...
Mike Kaplan
Purdue \'10 CRJ-700 FO

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Don Desfosse

  • ATC Instructor
  • 5796
Re: RNAV DP Discussion, Tips and Tricks
« Reply #7 on: October 21, 2011, 11:30:59 pm »
Cool, thanks for the insight, KN!
Don Desfosse (DO)
Division Director Emeritus, VATUSA
ATM Emeritus, Boston ARTCC

Boston ARTCC - Where Excellence is Routine!